Memory is one type of integrated circuitry, and may be used in computer systems for storing data. Integrated memory is usually fabricated in one or more arrays of individual memory cells. The memory cells are configured to retain or store memory in at least two different selectable states. In a binary system, the states are considered as either a “0” or a “1”. In other systems, at least some individual memory cells may be configured to store more than two levels or states of information.
There is a developing interest in memory cells which have programmable material provided between a pair of electrically conductive electrodes. Such memory cells may be referred to as cross-point memory cells.
Programmable materials suitable for utilization in cross-point memory will have two or more selectable and electrically differentiable memory states. The multiple selectable memory states can enable storing of information by an individual memory cell. The reading of the cell comprises determination of which of the memory states the programmable material is in, and the writing of information to the cell comprises placing the programmable material in a predetermined memory state.
Some memory cells utilize multiple discrete materials between the electrodes to create the programmable material. Such memory cells may be programmed by moving oxygen species (for instance, oxygen ions) within and/or between the materials. Memory devices that utilize migration of mobile charge carriers to transition from one memory state to another are sometimes referred to as Resistive Random Access Memory (RRAM) cells.
At least one of the materials utilized in such RRAM may be a conductive metal oxide (for instance, a combination of Pr, Ca, Mn and O; which is commonly referred to as PCMO). It can be difficult to consistently form metal oxide having uniform desired characteristics (for instance, high conductivity) across an array of memory cells. Accordingly, it is desired to develop new methods for forming conductive metal oxide within RRAM cells.